From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: Re: [RFC][PATCH 0/7] Clone PTS namespace Date: Fri, 25 Apr 2008 12:47:27 -0700 Message-ID: References: <20080408215333.GA8799@us.ibm.com> <47FC138B.4070408@zytor.com> <1207779313.16926.12.camel@x61.ebiederm.org> <20080410015955.GA18227@sergelap.austin.rr.com> <1207812980.7509.25.camel@x61.ebiederm.org> <20080422142539.GA12623@sergelap.austin.ibm.com> <20080423143610.GA13718@sergelap.austin.ibm.com> <20080423175749.GA17618@sergelap.austin.ibm.com> <20080425192102.GA17896@sergelap.austin.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <20080425192102.GA17896@sergelap.austin.ibm.com> (Serge E. Hallyn's message of "Fri, 25 Apr 2008 14:21:02 -0500") Sender: linux-kernel-owner@vger.kernel.org To: "Serge E. Hallyn" Cc: "H. Peter Anvin" , Containers , clg@fr.ibm.com, linux-kernel@vger.kernel.org, Pavel Emelyanov , Benjamin Thery List-Id: containers.vger.kernel.org "Serge E. Hallyn" writes: > Heh, well I tried several approaches - adding tag_ops to kset, to ktype, > etc. Finally ended up just calling sysfs_enable_tagging on > /sys/kernel/uids when that is created. It's now working perfectly. Sounds good. >> I suspect since you are working on this and I seem to be stuck >> in molasses at the moment it makes sense to figure out what it >> will take to handle the uid namespace before pushing these >> patches again. > > I had ported your patches to 2.6.25, but Benjamin in the meantime ported > them to 2.6.25-mm1. Since that's closer to the -net tree it's a more > useful port, so I'll let him post his patchset. Then I'll send the > userns patch on top of that. While I'm not actually able to send > network traffic over a veth dev (I probably am still not setting it up > right), I am able to pass veth devices into network namespaces, and the > user namespaces are properly handled. > > I believe Benjamin did notice a problem with some symlinks not existing, > and I think we want one more patch on top of yours removing the > hold_net() from sysfs_mount, which I don't think was what you really > wanted to do. By simply removing that, if all tasks in a netns go away, > the netns actually goes away and a lookup under a bind-mounted copy of > its /sys/class/net is empty. I will have to look, I need to refresh myself on where all of this code is. I think hold_net was what I wanted. A record that there is a user but not something that will keep the network namespace from going away. Essentially hold_net should be a debugging check rather then a real limitation. > Anyway the patches should be hitting the list next week. Cool. We can figure out what we need to do to merge them from there. >> Taking a quick look and having a clue what we will need to >> do for a theoretical device namespace is also a possibility. > > I'm not sure I'm familiar enough with the kobject/class/sysfs/device > relationships yet to comment on that. It doesn't look like it should > really be a problem, though simply adding tags to every directory > under /sys/class (/sys/class/tty, /sys/class/usb_device, etc) doesn't > seem like necessarily the nicest way to go... True. And the goal is something maintainable. There are still a lot of implications of a device namespace left unexamined so we shall see. Eric